The invention relates to a central locking system (ZVA) for a motor vehicle and more specifically to a central locking system for doors, tailgates or trunks, gasoline cap lids, and flaps of containers arranged in the passenger space, for example gloveboxes, small luggage compartments etc.
A ZVA of the relevant generic type is known from German Patent Specification No. 3,531,349.
It is also already known to equip flap fastenings located in the passenger space of a motor vehicle, for example the glovebox and additional storage spaces, with closures to be actuated by a key. Thus, these flap fastenings can each be locked against unauthorized access.
Such an arrangement is found, for example, in estate cars manufactured by Daimler-Benz, assignee of the present application, and is mentioned expressly in the operating instructions for these. The operating instructions also note that the tailgate lid fastening can be brought, as a result of key actuation of its closing point, into a locked closing position disconnected from the ZVA. Re-release of the tailgate lid fastening is then possible only as a result of a renewed key actuation of its closing point and not by the ZVA from another closing point.
Vehicles which can be driven and parked with an open canopy top have lacked a convenient ZVA which enables the vehicle user to lock centrally storage and luggage compartments in the passenger space, on the one hand jointly with the vehicle doors and the tailgate lid and on the other hand arbitrarily independent of these, against unauthorized access as a result of key actuation of a particular individual closing point.
The object of the invention is to develop a ZVA of the relevant generic type in the way indicated.
According to the invention, this object is achieved as follows.
The central control circuit (ZS) of the ZVA can also be operated as a result of key actuation of an additional closing point provided in the passenger space and coupled to a control switch. This additional closing point is in addition to the closing points at the doors and trunk lid.
A change-over device is inserted in connections between the actuating elements for door and trunk lid fastenings and the ZS and between the actuating elements for container flap fastenings and the ZS. Controlled by the ZS and switch signals from various closing points or control switches, the ZS connects to the ZS of its drive means (for example, dual pressure pump) for the actuating elements either only the door fastening and lid fastening actuating elements or only the flap-fastening actuating elements or, in response to a single switch command, all the actuating elements jointly.
An identification arrangement at those closing points which can be released and locked from outside the vehicle by the key and from inside the vehicle by an interior actuating handle, feeds a key recognition signal to the ZS when a key is used. As a result of the relationship of the key recognition signal to a change-over signal from a control switch assigned to the actuated closing point, a distinction is made in the switch logic of the ZS as to whether the ZS was actuated from outside or from inside.
If the vehicle is locked from inside, the flap-fastening actuating elements are not operated with the door locking, since it can be assumed that a vehicle user is in the passenger space and, although wanting to know that the doors and the tailgate lid of the vehicle are protected against unauthorized entry, even during driving, nevertheless still wishes to have free access to the containers in the passenger space.
Separate central locking of the container flap fastenings is possible, however, by locking the additional closing point in the passenger space.
Advantageously, a master key/secondary key (HS/NS) system of a type known per se can also be used for the ZVA disclosed here.
Thus, HS and NS can be used at the driver/front-seat passenger door closing points, while the additional closing point in the passenger space can be actuated only by the HS in a known way.
Then deviating from the state of the art, the identification arrangement can advantageously be designed so that it generates its key recognition signal even when the NS is used.
Further advantageous designs of the ZVA according to the invention emerge from the use of a storage circuit connected to the key identification for assuming a set state in response to a locking signal from one of the door or lid switches and allowing renewed operation of the central control unit only as a result of key actuation of one of the door or trunk closing points with the effective release. A logic circuit is provided to allow renewed activation of the central control circuit by a signal from the trunk lid closing point, or by the simultaneous occurrence of a release signal from the door closing point and a key recognition.
The central control circuit can include a dual pressure pump driven by an electric motor and fluid overpressure and underpressure elements in combination with a solenoid valve as the change-over device. The central control circuit controls the motor pump and solenoid valve to effectuate the appropriate operation. Separate circuits are provided for the door fastening and lid fastening elements from the flap fastening elements. Threshold switches are provided to provide appropriate feedback signals and sequence control of the operation.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.